6 days later

I made a couple of small changes:

  • If threading holes is not your thing you can use one 65mm long M5 bolt all the way through for the ball bearings and square M6 10x10x3 DIN 562 nuts at the inside to secure the print nozzles (hex nuts are to thick and do not fit). I made the necessary cut-outs in the endcaps to accommodate for such nuts if needed.

  • For the purpose of measuring ungripped and uncut clubs the hole is used; but for measuring ungripped clubs already cut to length, I incorporated an aligment notch at 1/8"" that I call “shaft catcher” in the 3D printed butt endcap. A grip is bigger in diameter than a shaft, so a grip slides unhindered under that little notch right to the 14” point while a shaft sitting slightly higher is stopped at 1/8” distance (the thickness of the butt of a grip) by that notch.

The STL's for both endcaps and the DXF-model have been updated.

I used a cd with a notch cut in it to find the balance point of the club, a scale to get the weight and a ruler to measure length of club and length to balance point. With that info you can calculate swing weight. Set it up in a spreadsheet and your good to go.

DISCLAIMER

This online calculator estimates lorythmic swingweight of a club based upon a simplified version of the swingweight formula that allows you to approximate the function of a true swingweight scale using a tape measure and digital scale.

The formulla is not an approximation but corresponds to how a swingweight scale functiones. The "problem" with this method is measuring the balance point with enough accuracy. A swingweight scale is just more accurate.

Accurate swingweight calculations require separate measurement of grip weight, shaft weight and head weight before assembly.

Not even close, If you don't know the centre of gravity (balance point) of all those components that method will be an estimate.

Funny enough the Lorythmic scale has 2 definitions : one swingweight being 50 grams or 1.75 ounce; D-0 is 121 swingweights in grams and 122 swingweights in ounces (6050 gram-inch = 213.5 ounce-inch). So who cares if a club measures D-1.5 or D-1.1; most people do not even feel the difference of a whole swingweight.

The formulla is simple enough :

weight in ounce x (balance point in inch - 14") /1.75 - 82 or weight in grams x (balance point in inch - 14")/50 - 81 gives the Lorythmic swingweight were the first digit is replaced by the corresponding lettter in the alfabet.

A swingweight scale on the basis of a digital gram scale does that last calculation mechanicly (put the club on a -14" fulcrum, measure 10gram @ 5" = /50, calibrate the scale to 300g @ 13.5" = -81 swingweights"): again replace the first digit of the read-out by the corresponding letter in the alfabet to have the Lorythmic swingweight.

I've added the STL's for a 1-1/2"x1"x16ga steel tube as well, for those whose hardware store isn't metric.